This isn't the first time Kelso has performed on the Broadway stage. In fact, he originated the role of 'Harry' in Kinky Boots before taking on the lead. He made his debut in 2005 as Sky in MAMMA MIA! and also starred as 'Fiyero' in the 1st National Tour of WICKED.

Below, BroadwayWorld spoke with Kelso about transitioning to his new role in the Tony-winning hit!

Let's just jump right in -- how's it going in the new part?

Things are going pretty well. It's been quite a shift for sure, but it's really starting to settle in. It's so great to be able to play with everybody else and start to take hold of this role.

Right, you were playing 'Harry' before, so what's it like shifting from that role to another in the same show?

Oh my gosh, it's such a unique, fun and weird experience. The four days around when Stark left and I took over were the strangest. So many emotions were going through my head at the time. Saying goodbye to Stark - I became friends with him throughout this process, we even knew each other before KINKY BOOTS, so it was sad to say goodbye to him. And to say goodbye to my old role of 'Harry', and the factory worker 'Crispin', that I had created... And it just kind of was symbolic of this whole process in a way; the whole journey of the show has just been so fantastic and that was my perspective, and so to say goodbye to that was really strange. But then at the same time to have the excitement to be able to take over for Stark and to be able to play this amazing role -- that I loved understudying -- it's just such a cool experience that is unique to this happening, to getting moved up in the show that you're already a part of.

And I'm sure it changes with the scope of the new role you're playing. Do you have a favorite thing about playing 'Charlie'?

For one thing, my dressing room has a lot less stairs. [Laughs.] The way the backstage is set up, my old dressing room was on the very top floor on the tower of dressing rooms; it was like five or six flights up. But I also just love being able to be involved in the story in this way, to be able to really get my hands dirty with the actual role. And the turn that 'Charlie' takes in the show is so spectacular and fun. It changes a little bit every night, and I don't imagine that it will ever not change. I'll find something new every performance, and that's been really fun so far. Probably my favorite thing.

So you said you knew Stark before KINKY BOOTS. How did you meet?

It was sort of through friends of friends. He did JOURNEY'S END, is when I first I met him. I was in MAMMA MIA! at the time, and I don't remember exactly how, but we ended up hanging out one night and singing karaoke with a bunch of friends. And then I remember later -- it was Easter Bonnet, I think -- they did "The Journey Boys", it was like a JERSEY BOYS thing for their skit -- and I remember meeting him backstage again and talking. It was before he had done AMERICAN IDIOT or any musical theatre, and I was like, "You should do this, you sound great." And he said he that he remembered that. And then I knew friends in AMERICAN IDIOT, so a lot of just kind of hanging out outside of shows socially, but we were never really close until we started working on KINKY BOOTS.

Did he give you any advice before you stepped into the role, or was it something you tackled on your own?

He's kind of just let me do with it what you will. Because I was around so much for his development of the role, I heard all the things that Jerry [Mitchell] mentioned to him, and I've been really fortunate to be able to work on the role with Jerry himself. And I think Stark knew that all the advice had already been kind of given to me. And he was like, "Here have fun with it," and he would say, you know, "If you have any questions, feel free to ask," but he felt pretty confident with how well we're prepared here.

Do you have a favorite number or scene from the show?

The one that comes to mind is "Soul of a Man" and the scene leading up to it. It's one of those scenes that every day, I dread doing it and I love doing it. Just because it's so rich and it takes so much energy and focus, and those are the kind of things that as actors I think we really love doing. Some days when you're run down or tired, those are the scenes that are the biggest mountains, but you conquer them, and once you do them throughout the show, they're so much fun. They're intense, and it's great. And besides that, I love the Finale, because you get to shake a lot of other stuff off for a little bit and just have fun and play to the audience and watch their faces light up and really get involved with the show.

This is a little bit of a tangent, but I collect all of the Saturday Intermission Pics each weekend, and I always look forward to seeing your Tweets from backstage. I just wanted to let you know!

That's awesome! We have so much fun doing those. We were actually talking about how we're going to continue that tradition. All those pictures that I posted take place in the men's quick-change room, and we set it with a pattern of having that flag [the Union Jack] in the background, and that's our staple now. I think they're going to keep the tradition going. Once I'm kind of settled into my own space up here, they'll be doing their own thing down there.

Is there anything else about the show or your new role that you wanted to add?

This whole show is such a great, amazing blessing in my life, and to be able to be a part of another transformation -- going from the readings to Chicago to opening to the Tonys and now being able to take over for 'Charlie' -- has just been so incredible, and I couldn't be happier.

Next in line for the New Year's cast changes, Jeanna de Waal will join KINKY BOOTS as 'Lauren,' beginning March 4 (replacing Annaleigh Ashford, who leaves to join the cast of Showtime's MASTERS OF SEX), and Jake Odmark will board the ensemble in the roles previously played by Kelso. Billy Porter, last year's Tony Award-winner for Best Actor in a Musical, will remain with the show.

For more about Andy, visit andykelso.com or follow him on Twitter @NakedlySo.